Hypertension is harmful to dialysis patients and should be controlled

Managing hypertension is among the commonest and most challenging features of end-stage renal disease and many clinical trials have shown the benefit of treating hypertension in the general population. If associations between blood pressure levels and cardiovascular outcomes in dialysis patients mirrored those seen in general population studies, one could argue that dialysis population-specific antihypertensive trials are unnecessary. Associations between blood pressure levels and outcomes are complex in this population. Naturally, comparisons of observational and experimental findings within intervention in patients with chronic kidney disease often show a surprising degree of disparity. In addition, the possibility of serious unmeasured co-morbid illnesses masking the true causal relationship between blood pressure and outcomes in this population looms large. Unfortunately, therefore, observational studies appear to be highly unreliable guides to identifying the truth regarding optimal management of hypertension. It appears, then, that controlled trials, alone, can inform appropriate treatment. Of late, intervention trials of antihypertensives in dialysis patients have begun to emerge. Though mostly small, less than definitive, and heterogeneous regarding patient selection, interventions and outcomes, several suggest net benefit and none suggests net harm. As dialysis patients are at vast cardiovascular risk, these findings suggest that aggressive treatment of hypertension should be the default approach, until large clinical trials show otherwise.